Electric metal-working machine.



E. THOMSON. ELECTRIC METAL WORKING MACHINE.

APPLICATION FILED MAR. 4, 1911. I

1,045,91 1. Patented Dec. 3, 1912.

WITNESSES 5 INVENTOR (g I x EBLy/ u THOMSON on rnn omens PATENT oFrioE.

ELIHU THOMSON, OF SWAEPSGOTT, MASSACHUSETTS, ASSIGNOR E THOMSON ELECTRIC WELDING COMPANY, 01? LYNN, MASSACHUSETTS A CORPQRATION OF MASSACHUSETTS.

nmcrmo ivinmri-wonmno MACHINE.

$p eclficati'on of ietters Ifatent.

rammed Dec. 311,913

Application filed mama 4t, zen. Serial No. 812,2456.

To all whom it may concern:

lleit known thatl, Erin-in 'lnoirsos, a citizen of the United States,-a'ml a resident of Swamps-colt, in the county of Essex and State of lllassachusetts, have invented con tain new and useful Improvements in Electric Metal-Writing ll'laehines, of which the following is a specification. 4

My invention relates to that part of an electric metal working apparatnsdiy which the work is clamped or held in position and is supplied with heating electric current.

lily inrention provides improved means for doing accurate work and its object is. generally stated, to rigidly secure the pieces for electric welding or other operation in the greatest possible exactness of position and at the same time provide for thesupply ot'rurrent thereto by means of a good-cook ducting nietallike copper.

in electric welding machines as ordinarily ('tIli.-tll!(l( i the work is clamped rig- .idl in blocks or jaws which are usually made'ot sot't copper or other good conduct ing material and which jaws form the tee minals of the source of heating current and supply current to the work. liy reason of the nature of this conducting material. it is liable to get out of shape on account of the heavy pressure of the work nhen rigidly clamped thereon. This diiiiculty is in creased by reason of the fact that the block is locally heated by the passage oi the cur rent, so that the part supporting: the metal to be welded softens and is more liable to become deformed by the pressure of the work thereon.

The object; of my invention is to avoid this ditliculty, and while peg-sp itting the electric current to be fed into o work at? close as is desired in thoportion thereof I which is to be. locally heated for the wc lding or other operation, to permit the work to be rigidly and firmly held or clamped in blocks or supports of hard metal, not subject to deformation and properly mounts ed to maintain the alinement oi the work on a rigid bed. I I

To these ends my invention consists in the no'vol constructions and combinations of work clamping and current supplying devices hereinafter more particularly described ami'thcn specified in the claims.

ance with my invention,

tortlin Some forms in which my invention rm. he realized are shown in the accompanyinkftsb drawings, in which- I Figure 1 is a general end elevation oi. one form of the apparatus. Fig. 2 is amend" elevation of a, modification and-Fig.' 3 is sideeleration of the same.- v tit)v The drawing Fig. 1 shows the invention embodied in an apparatus particularly" adapted to the holding of a plate of metal" rigidly or accurately in position and the supplying of current thereto in accord The plate 8 is shown end on or in the direction or line of the pressure which is applied in the uslill or proper way to the heated section of work to etiect the welding or other operation; "the work support comprises any desired number of support pieces 3 which, as before. are made. of steel or other suitable hard, metal and these are properly mounted 'ot1- the bed 1, as already described. The clamp log devices comprise by preference clamp ing jaws 20 pirotallv mounted as shown on the ends of an equalizing lever .31 which is itselt pivoted on the lever 22, the latteraifmeans for applying pressure through the fulcrum of the eqiializing lev er ill to tho pivotally mounted clamping juws' 20. The latter being arranged in line trans- -\'ersoly to the work, itwill boobvioras that an equalization of pressure from lever 22 will occur across the whole extent-0f the plate 8 to which it is desired to apply. the pressure for holding the, same rigidly down npon its support. Between the piece! 3-3.----l-fl and substantially in the plane of the. clamping pressure are copper blocks attached to one of the terminals of a. welding transformer secondary, and these blocks tre'lield upward toward the plate8 to a limited range by powerful springs under them. Another new to be welded to plate 8 would he held in the same way and one. of the holding arrangements would be, of course, movable so as to press the parts up together and forming the weld. It will thus be seen that the current is carried into the work piece'hy the blocks l1-li while the support in the accurate position is 'sccurcd by the pieces 3-3-3-3 upon whi'clr'vthe, work actually rests.

As will be seen th c i'unctions of current W ou i conduction and support are separated in the structure while such supports are made of firm hard material, like steel, not easily subject to deformation. It will further be seen that as the blocks or electrodes engage the work at a portion thereof not directly engaged by the rigid clamping devices and are in a sense independent of the same, they will not themselves be subject to the deforming action of the rigid clamps, while nevertheless they will efiiciently supply the heat-ing current to the work, in the general plane of the clamping pressure, and therefore as close up to the section to be heated as the rigid clamping devices themselves. Yet, as will be seen, the operation of clamping the work by the rigid clamping devices produces a good and firm contact of the current supplying electrode with the work.

Figs. 2 and 3 show how the same principle may be applied to a concentric chuck where the jaws 4-l4= are of steel or hard metal and'arranged to be adjusted to hold the work piece which is a bar, shown on end, marked-9, accurately. Between these jaws 4-H which may be drawn with great force and accurate placing upon the work piece 9, are other jaws 1212-12 pressed down upon the bar 9 and contacting electrically with the same, such jaws being made of metal of high conductivity, like copper, and being connected by large section conductors to the welding transformer, all of these jaws or conducting blooks1212-12 bein of course, connected'to one terminal while a similar structure accurately'placed on a bed with relation to this structure would be at tached to the other terminal. As will be seen, the current supplying jaws or electrodes 12 make contact with' the work substantially in the plane of the clamping pressure but are i dependent of the rigid clamping devices in the sense that they are not subjected tofthe deforming action of the same'in firmly clamping the work against: deviation from alinement.

hat I claim as my invention is: I 1. In an electric metal working apparatus.

the combination of a work holder provided Work holding device.

2. In an electric metal working apparatus, the combination of an equalizing lever having means for applying pressure through its fulcrum and clamping jaws pivotally mounted thereon at opposite sides of the fulcrum.

3. In a Work holder for electric metal working apparatus, a support piece of hard metahmeans for clamping the work rigidly against the same and a supplemental spring seated current supplying block of soft metal arranged in the line of and receiving the clamping pressure.

4. In a work holder for electric metal working apparatus, two or more support pieces of hard metal combined with an intermediate current supplying piece consisting of soft metal arranged in the general plane of clamping pressure.

5. In a work holder for electric metal Working apparatus, two or more rigid support pieces of hard metal combined with an intermediate spring seated current supplying piece of soft metal arranged in the general plane of clamping pressure Signed at Lynn in the county of Essex and State of h lassachusotts this first day of March A. D. 1911.

ELIHU THOMSON.

Witnesses:

JOHN A. McMANU-s, J12, CHARLES A. Bannann. 

